1. Field of the Invention
The present invention concerns a softening agent and more particularly, it relates to a concentrated softening agent for use in clothing, which agent exhibits less viscosity increase with age and is capable of providing various kinds of fabrics with excellent softness and antistatic property.
2. Description of the Prior Art
During wearing and repeated washing of clothings, fabric processing chemicals are washed out or the clothings per se are hardened due to deterioration whereby to result in an undesired feel. In view of the above, softening agents capable of providing fabrics with softness and antistatic property have generally often been used in homes.
At present, most of the commercially available, home use, softening agents comprise, as the main ingredient, cationic surface active agents having 1-2long chain alkyl groups in one molecule, for example, di(hardened tallow alkyl)dimethylammonium salts.
These softening base materials comprising such quaternary ammonium salts as the main ingredient are less water soluble and are usually produced in the form of 3 to 5 wt% aqueous dispersion or emulsion. Along with the increase of clothing for which the softening agents are used, there has keenly been demanded a concentrated softening agent for use in clothing which agent is a highly concentrated aqueous dispersion, for reducing the distribution cost and packaging cost, and reducing the amount of storage space required in homes and shops.
However, if the concentration of the softening base material exceeds 5% by weight, the viscosity of the aqueous dispersion is remarkably increased so as to cause various handling troubles.
For producing softening agents at such a high concentration, there have been known, for example,
(1) a method of adding a water soluble cationic surface active agent, PA1 (2) a method of adding an ethylene oxide adduct of a higher alcohol or alkyl phenol, PA1 (3) a method of adding urea or ethylene glycol and PA1 (4) a method of adding a water soluble salt. PA1 (a) from 10 to 20% by weight of one or more of quaternary ammonium salts, PA1 (b) from 0.5 to 3% by weight of an addition product of (i) from 10-50 mols of alkylene oxide containing, as an essential ingredient, ethylene oxide, with (ii) one mol of an unsaturated or branched alcohol having 12 to 24 carbon atoms or an unsaturated or branched aliphatic acid having 12 to 24 carbon atoms, PA1 (c) from 0.5 to 2.0% by weight of a monohydric alcohol having 1 to 3 carbon atoms, PA1 (d) from 3 to 15% by weight of a di- or tri-valent polyol having 2 to 3 carbon atoms, PA1 (e) from 0.05 to 0.4% by weight of an inorganic salt, and PA1 (f) from 0.3 to 5% by weight of one or more of polyether compound or derivative thereof which is prepared by adding an alkylene oxide containing ethylene oxide as the essential ingredient to a compound having three or more active hydrogen atoms, in which the total weight for the polyoxyethylene chain moiety is more than 60% of the entire weight and the molecular weight is from 5,000 to 2,000,000. PA1 R.sub.2a : saturated or unsaturated, linear or branched C.sub.8 -C.sub.24 aliphatic hydrocarbon group or hydroxy-substituted aliphatic hydrocarbon group, PA1 R.sub.3a, R.sub.4a, R.sub.6a : C.sub.1 -C.sub.3 alkyl group, hydroxy-substituted alkyl group or ##STR2## in which n=1-10, Ya=hydrogen or CH.sub.3, R.sub.5a : saturated or unsaturated branched C.sub.24 -C.sub.36 aliphatic hydrocarbon group or substituted aliphatic hydrocarbon group; PA1 R.sub.7a, R.sub.8a : saturated or unsaturated linear or branched C.sub.7 -C.sub.21 aliphatic hydrocarbon group or substituted aliphatic hydrocarbon group; PA1 A, B: C.sub.1 -C.sub.3 alkylene group; PA1 Xa: CH.sub.3 SO.sub.4, C.sub.2 H.sub.5 SO.sub.4, C.sub.n H.sub.2n+1 COO, in which n=0-17, C.sub.n H.sub.2n+1 OPO.sub.3 in which n=8-18, HOCH.sub.2 COO, ##STR3## halogen.
However, the methods (1)-(3) can provide no satisfactory effect since the concentration is insufficient or the viscosity increases with time.
In the case of the method (4), although an effect of lowering the initial viscosity can be obtained, there is no satisfactory effect of suppressing the increase of the viscosity with aging. In addition, if the salt is added in a great amount, the aqueous dispersion tends to be separated and, accordingly, satisfactory concentrated softening agents for use in clothing have not yet been obtained.